The purpose of this project is the study of genome structure and function of the Aleutian disease of mink parvovirus (ADV). In the past year we have completed sequencing of ADV-G genome and found that its overall structure resembles that of other nondefective parvoviruses. A portion of the "left-hand" open reading frame (ORF) has been expressed in bacteria and shown to code for the 71,000 dalton nonstructural protein of ADV. Sequence heterogeneity for the structural protein region of the ADV genome has been demonstrated with the heterogeneity observed might reflect host range determinants involved with pathogenicity. Finally, study of the ADV transcription program has been initiated. Three major polyadenylated RNAs have been detected; 4.5 kb, 2.6 kb, and 0.9 kb.